//========================================================================
// GLFW 3.3 Win32 - www.glfw.org
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Marcus Geelnard
// Copyright (c) 2006-2019 Camilla Löwy <elmindreda@glfw.org>
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would
//    be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
//    be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
//    distribution.
//
//========================================================================
// Please use C89 style variable declarations in this file because VS 2010
//========================================================================

#include "internal.h"

#include <stdlib.h>
#include <malloc.h>

static const GUID _glfw_GUID_DEVINTERFACE_HID =
    {0x4d1e55b2, 0xf16f, 0x11cf, {0x88, 0xcb, 0x00, 0x11, 0x11, 0x00, 0x00, 0x30}};

#define GUID_DEVINTERFACE_HID _glfw_GUID_DEVINTERFACE_HID

#if defined(_GLFW_USE_HYBRID_HPG) || defined(_GLFW_USE_OPTIMUS_HPG)

#if defined(_GLFW_BUILD_DLL)
#warning "These symbols must be exported by the executable and have no effect in a DLL"
#endif

// Executables (but not DLLs) exporting this symbol with this value will be
// automatically directed to the high-performance GPU on Nvidia Optimus systems
// with up-to-date drivers
//
__declspec(dllexport) DWORD NvOptimusEnablement = 1;

// Executables (but not DLLs) exporting this symbol with this value will be
// automatically directed to the high-performance GPU on AMD PowerXpress systems
// with up-to-date drivers
//
__declspec(dllexport) int AmdPowerXpressRequestHighPerformance = 1;

#endif // _GLFW_USE_HYBRID_HPG

#if defined(_GLFW_BUILD_DLL)

// GLFW DLL entry point
//
BOOL WINAPI DllMain(HINSTANCE instance, DWORD reason, LPVOID reserved) {
  return TRUE;
}

#endif // _GLFW_BUILD_DLL

// Load necessary libraries (DLLs)
//
static GLFWbool loadLibraries(void) {
  _glfw.win32.winmm.instance = LoadLibraryA("winmm.dll");
  if (!_glfw.win32.winmm.instance) {
    _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
                         "Win32: Failed to load winmm.dll");
    return GLFW_FALSE;
  }

  _glfw.win32.winmm.GetTime = (PFN_timeGetTime)
      GetProcAddress(_glfw.win32.winmm.instance, "timeGetTime");

  _glfw.win32.user32.instance = LoadLibraryA("user32.dll");
  if (!_glfw.win32.user32.instance) {
    _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
                         "Win32: Failed to load user32.dll");
    return GLFW_FALSE;
  }

  _glfw.win32.user32.SetProcessDPIAware_ = (PFN_SetProcessDPIAware)
      GetProcAddress(_glfw.win32.user32.instance, "SetProcessDPIAware");
  _glfw.win32.user32.ChangeWindowMessageFilterEx_ = (PFN_ChangeWindowMessageFilterEx)
      GetProcAddress(_glfw.win32.user32.instance, "ChangeWindowMessageFilterEx");
  _glfw.win32.user32.EnableNonClientDpiScaling_ = (PFN_EnableNonClientDpiScaling)
      GetProcAddress(_glfw.win32.user32.instance, "EnableNonClientDpiScaling");
  _glfw.win32.user32.SetProcessDpiAwarenessContext_ = (PFN_SetProcessDpiAwarenessContext)
      GetProcAddress(_glfw.win32.user32.instance, "SetProcessDpiAwarenessContext");
  _glfw.win32.user32.GetDpiForWindow_ = (PFN_GetDpiForWindow)
      GetProcAddress(_glfw.win32.user32.instance, "GetDpiForWindow");
  _glfw.win32.user32.AdjustWindowRectExForDpi_ = (PFN_AdjustWindowRectExForDpi)
      GetProcAddress(_glfw.win32.user32.instance, "AdjustWindowRectExForDpi");

  _glfw.win32.dinput8.instance = LoadLibraryA("dinput8.dll");
  if (_glfw.win32.dinput8.instance) {
    _glfw.win32.dinput8.Create = (PFN_DirectInput8Create)
        GetProcAddress(_glfw.win32.dinput8.instance, "DirectInput8Create");
  }

  {
    int i;
    const char* names[] =
        {
            "xinput1_4.dll",
            "xinput1_3.dll",
            "xinput9_1_0.dll",
            "xinput1_2.dll",
            "xinput1_1.dll",
            NULL};

    for (i = 0; names[i]; i++) {
      _glfw.win32.xinput.instance = LoadLibraryA(names[i]);
      if (_glfw.win32.xinput.instance) {
        _glfw.win32.xinput.GetCapabilities = (PFN_XInputGetCapabilities)
            GetProcAddress(_glfw.win32.xinput.instance, "XInputGetCapabilities");
        _glfw.win32.xinput.GetState = (PFN_XInputGetState)
            GetProcAddress(_glfw.win32.xinput.instance, "XInputGetState");

        break;
      }
    }
  }

  _glfw.win32.dwmapi.instance = LoadLibraryA("dwmapi.dll");
  if (_glfw.win32.dwmapi.instance) {
    _glfw.win32.dwmapi.IsCompositionEnabled = (PFN_DwmIsCompositionEnabled)
        GetProcAddress(_glfw.win32.dwmapi.instance, "DwmIsCompositionEnabled");
    _glfw.win32.dwmapi.Flush = (PFN_DwmFlush)
        GetProcAddress(_glfw.win32.dwmapi.instance, "DwmFlush");
    _glfw.win32.dwmapi.EnableBlurBehindWindow = (PFN_DwmEnableBlurBehindWindow)
        GetProcAddress(_glfw.win32.dwmapi.instance, "DwmEnableBlurBehindWindow");
    _glfw.win32.dwmapi.GetColorizationColor = (PFN_DwmGetColorizationColor)
        GetProcAddress(_glfw.win32.dwmapi.instance, "DwmGetColorizationColor");
  }

  _glfw.win32.shcore.instance = LoadLibraryA("shcore.dll");
  if (_glfw.win32.shcore.instance) {
    _glfw.win32.shcore.SetProcessDpiAwareness_ = (PFN_SetProcessDpiAwareness)
        GetProcAddress(_glfw.win32.shcore.instance, "SetProcessDpiAwareness");
    _glfw.win32.shcore.GetDpiForMonitor_ = (PFN_GetDpiForMonitor)
        GetProcAddress(_glfw.win32.shcore.instance, "GetDpiForMonitor");
  }

  _glfw.win32.ntdll.instance = LoadLibraryA("ntdll.dll");
  if (_glfw.win32.ntdll.instance) {
    _glfw.win32.ntdll.RtlVerifyVersionInfo_ = (PFN_RtlVerifyVersionInfo)
        GetProcAddress(_glfw.win32.ntdll.instance, "RtlVerifyVersionInfo");
  }

  return GLFW_TRUE;
}

// Unload used libraries (DLLs)
//
static void freeLibraries(void) {
  if (_glfw.win32.xinput.instance)
    FreeLibrary(_glfw.win32.xinput.instance);

  if (_glfw.win32.dinput8.instance)
    FreeLibrary(_glfw.win32.dinput8.instance);

  if (_glfw.win32.winmm.instance)
    FreeLibrary(_glfw.win32.winmm.instance);

  if (_glfw.win32.user32.instance)
    FreeLibrary(_glfw.win32.user32.instance);

  if (_glfw.win32.dwmapi.instance)
    FreeLibrary(_glfw.win32.dwmapi.instance);

  if (_glfw.win32.shcore.instance)
    FreeLibrary(_glfw.win32.shcore.instance);

  if (_glfw.win32.ntdll.instance)
    FreeLibrary(_glfw.win32.ntdll.instance);
}

// Create key code translation tables
//
static void createKeyTables(void) {
  int scancode;

  memset(_glfw.win32.keycodes, -1, sizeof(_glfw.win32.keycodes));
  memset(_glfw.win32.scancodes, -1, sizeof(_glfw.win32.scancodes));

  _glfw.win32.keycodes[0x00B] = GLFW_KEY_0;
  _glfw.win32.keycodes[0x002] = GLFW_KEY_1;
  _glfw.win32.keycodes[0x003] = GLFW_KEY_2;
  _glfw.win32.keycodes[0x004] = GLFW_KEY_3;
  _glfw.win32.keycodes[0x005] = GLFW_KEY_4;
  _glfw.win32.keycodes[0x006] = GLFW_KEY_5;
  _glfw.win32.keycodes[0x007] = GLFW_KEY_6;
  _glfw.win32.keycodes[0x008] = GLFW_KEY_7;
  _glfw.win32.keycodes[0x009] = GLFW_KEY_8;
  _glfw.win32.keycodes[0x00A] = GLFW_KEY_9;
  _glfw.win32.keycodes[0x01E] = GLFW_KEY_A;
  _glfw.win32.keycodes[0x030] = GLFW_KEY_B;
  _glfw.win32.keycodes[0x02E] = GLFW_KEY_C;
  _glfw.win32.keycodes[0x020] = GLFW_KEY_D;
  _glfw.win32.keycodes[0x012] = GLFW_KEY_E;
  _glfw.win32.keycodes[0x021] = GLFW_KEY_F;
  _glfw.win32.keycodes[0x022] = GLFW_KEY_G;
  _glfw.win32.keycodes[0x023] = GLFW_KEY_H;
  _glfw.win32.keycodes[0x017] = GLFW_KEY_I;
  _glfw.win32.keycodes[0x024] = GLFW_KEY_J;
  _glfw.win32.keycodes[0x025] = GLFW_KEY_K;
  _glfw.win32.keycodes[0x026] = GLFW_KEY_L;
  _glfw.win32.keycodes[0x032] = GLFW_KEY_M;
  _glfw.win32.keycodes[0x031] = GLFW_KEY_N;
  _glfw.win32.keycodes[0x018] = GLFW_KEY_O;
  _glfw.win32.keycodes[0x019] = GLFW_KEY_P;
  _glfw.win32.keycodes[0x010] = GLFW_KEY_Q;
  _glfw.win32.keycodes[0x013] = GLFW_KEY_R;
  _glfw.win32.keycodes[0x01F] = GLFW_KEY_S;
  _glfw.win32.keycodes[0x014] = GLFW_KEY_T;
  _glfw.win32.keycodes[0x016] = GLFW_KEY_U;
  _glfw.win32.keycodes[0x02F] = GLFW_KEY_V;
  _glfw.win32.keycodes[0x011] = GLFW_KEY_W;
  _glfw.win32.keycodes[0x02D] = GLFW_KEY_X;
  _glfw.win32.keycodes[0x015] = GLFW_KEY_Y;
  _glfw.win32.keycodes[0x02C] = GLFW_KEY_Z;

  _glfw.win32.keycodes[0x028] = GLFW_KEY_APOSTROPHE;
  _glfw.win32.keycodes[0x02B] = GLFW_KEY_BACKSLASH;
  _glfw.win32.keycodes[0x033] = GLFW_KEY_COMMA;
  _glfw.win32.keycodes[0x00D] = GLFW_KEY_EQUAL;
  _glfw.win32.keycodes[0x029] = GLFW_KEY_GRAVE_ACCENT;
  _glfw.win32.keycodes[0x01A] = GLFW_KEY_LEFT_BRACKET;
  _glfw.win32.keycodes[0x00C] = GLFW_KEY_MINUS;
  _glfw.win32.keycodes[0x034] = GLFW_KEY_PERIOD;
  _glfw.win32.keycodes[0x01B] = GLFW_KEY_RIGHT_BRACKET;
  _glfw.win32.keycodes[0x027] = GLFW_KEY_SEMICOLON;
  _glfw.win32.keycodes[0x035] = GLFW_KEY_SLASH;
  _glfw.win32.keycodes[0x056] = GLFW_KEY_WORLD_2;

  _glfw.win32.keycodes[0x00E] = GLFW_KEY_BACKSPACE;
  _glfw.win32.keycodes[0x153] = GLFW_KEY_DELETE;
  _glfw.win32.keycodes[0x14F] = GLFW_KEY_END;
  _glfw.win32.keycodes[0x01C] = GLFW_KEY_ENTER;
  _glfw.win32.keycodes[0x001] = GLFW_KEY_ESCAPE;
  _glfw.win32.keycodes[0x147] = GLFW_KEY_HOME;
  _glfw.win32.keycodes[0x152] = GLFW_KEY_INSERT;
  _glfw.win32.keycodes[0x15D] = GLFW_KEY_MENU;
  _glfw.win32.keycodes[0x151] = GLFW_KEY_PAGE_DOWN;
  _glfw.win32.keycodes[0x149] = GLFW_KEY_PAGE_UP;
  _glfw.win32.keycodes[0x045] = GLFW_KEY_PAUSE;
  _glfw.win32.keycodes[0x146] = GLFW_KEY_PAUSE;
  _glfw.win32.keycodes[0x039] = GLFW_KEY_SPACE;
  _glfw.win32.keycodes[0x00F] = GLFW_KEY_TAB;
  _glfw.win32.keycodes[0x03A] = GLFW_KEY_CAPS_LOCK;
  _glfw.win32.keycodes[0x145] = GLFW_KEY_NUM_LOCK;
  _glfw.win32.keycodes[0x046] = GLFW_KEY_SCROLL_LOCK;
  _glfw.win32.keycodes[0x03B] = GLFW_KEY_F1;
  _glfw.win32.keycodes[0x03C] = GLFW_KEY_F2;
  _glfw.win32.keycodes[0x03D] = GLFW_KEY_F3;
  _glfw.win32.keycodes[0x03E] = GLFW_KEY_F4;
  _glfw.win32.keycodes[0x03F] = GLFW_KEY_F5;
  _glfw.win32.keycodes[0x040] = GLFW_KEY_F6;
  _glfw.win32.keycodes[0x041] = GLFW_KEY_F7;
  _glfw.win32.keycodes[0x042] = GLFW_KEY_F8;
  _glfw.win32.keycodes[0x043] = GLFW_KEY_F9;
  _glfw.win32.keycodes[0x044] = GLFW_KEY_F10;
  _glfw.win32.keycodes[0x057] = GLFW_KEY_F11;
  _glfw.win32.keycodes[0x058] = GLFW_KEY_F12;
  _glfw.win32.keycodes[0x064] = GLFW_KEY_F13;
  _glfw.win32.keycodes[0x065] = GLFW_KEY_F14;
  _glfw.win32.keycodes[0x066] = GLFW_KEY_F15;
  _glfw.win32.keycodes[0x067] = GLFW_KEY_F16;
  _glfw.win32.keycodes[0x068] = GLFW_KEY_F17;
  _glfw.win32.keycodes[0x069] = GLFW_KEY_F18;
  _glfw.win32.keycodes[0x06A] = GLFW_KEY_F19;
  _glfw.win32.keycodes[0x06B] = GLFW_KEY_F20;
  _glfw.win32.keycodes[0x06C] = GLFW_KEY_F21;
  _glfw.win32.keycodes[0x06D] = GLFW_KEY_F22;
  _glfw.win32.keycodes[0x06E] = GLFW_KEY_F23;
  _glfw.win32.keycodes[0x076] = GLFW_KEY_F24;
  _glfw.win32.keycodes[0x038] = GLFW_KEY_LEFT_ALT;
  _glfw.win32.keycodes[0x01D] = GLFW_KEY_LEFT_CONTROL;
  _glfw.win32.keycodes[0x02A] = GLFW_KEY_LEFT_SHIFT;
  _glfw.win32.keycodes[0x15B] = GLFW_KEY_LEFT_SUPER;
  _glfw.win32.keycodes[0x137] = GLFW_KEY_PRINT_SCREEN;
  _glfw.win32.keycodes[0x138] = GLFW_KEY_RIGHT_ALT;
  _glfw.win32.keycodes[0x11D] = GLFW_KEY_RIGHT_CONTROL;
  _glfw.win32.keycodes[0x036] = GLFW_KEY_RIGHT_SHIFT;
  _glfw.win32.keycodes[0x15C] = GLFW_KEY_RIGHT_SUPER;
  _glfw.win32.keycodes[0x150] = GLFW_KEY_DOWN;
  _glfw.win32.keycodes[0x14B] = GLFW_KEY_LEFT;
  _glfw.win32.keycodes[0x14D] = GLFW_KEY_RIGHT;
  _glfw.win32.keycodes[0x148] = GLFW_KEY_UP;

  _glfw.win32.keycodes[0x052] = GLFW_KEY_KP_0;
  _glfw.win32.keycodes[0x04F] = GLFW_KEY_KP_1;
  _glfw.win32.keycodes[0x050] = GLFW_KEY_KP_2;
  _glfw.win32.keycodes[0x051] = GLFW_KEY_KP_3;
  _glfw.win32.keycodes[0x04B] = GLFW_KEY_KP_4;
  _glfw.win32.keycodes[0x04C] = GLFW_KEY_KP_5;
  _glfw.win32.keycodes[0x04D] = GLFW_KEY_KP_6;
  _glfw.win32.keycodes[0x047] = GLFW_KEY_KP_7;
  _glfw.win32.keycodes[0x048] = GLFW_KEY_KP_8;
  _glfw.win32.keycodes[0x049] = GLFW_KEY_KP_9;
  _glfw.win32.keycodes[0x04E] = GLFW_KEY_KP_ADD;
  _glfw.win32.keycodes[0x053] = GLFW_KEY_KP_DECIMAL;
  _glfw.win32.keycodes[0x135] = GLFW_KEY_KP_DIVIDE;
  _glfw.win32.keycodes[0x11C] = GLFW_KEY_KP_ENTER;
  _glfw.win32.keycodes[0x059] = GLFW_KEY_KP_EQUAL;
  _glfw.win32.keycodes[0x037] = GLFW_KEY_KP_MULTIPLY;
  _glfw.win32.keycodes[0x04A] = GLFW_KEY_KP_SUBTRACT;

  for (scancode = 0; scancode < 512; scancode++) {
    if (_glfw.win32.keycodes[scancode] > 0)
      _glfw.win32.scancodes[_glfw.win32.keycodes[scancode]] = scancode;
  }
}

// Creates a dummy window for behind-the-scenes work
//
static GLFWbool createHelperWindow(void) {
  MSG msg;

  _glfw.win32.helperWindowHandle =
      CreateWindowExW(WS_EX_OVERLAPPEDWINDOW,
                      _GLFW_WNDCLASSNAME,
                      L"GLFW message window",
                      WS_CLIPSIBLINGS | WS_CLIPCHILDREN,
                      0,
                      0,
                      1,
                      1,
                      NULL,
                      NULL,
                      GetModuleHandleW(NULL),
                      NULL);

  if (!_glfw.win32.helperWindowHandle) {
    _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
                         "Win32: Failed to create helper window");
    return GLFW_FALSE;
  }

  // HACK: The command to the first ShowWindow call is ignored if the parent
  //       process passed along a STARTUPINFO, so clear that with a no-op call
  ShowWindow(_glfw.win32.helperWindowHandle, SW_HIDE);

  // Register for HID device notifications
  {
    DEV_BROADCAST_DEVICEINTERFACE_W dbi;
    ZeroMemory(&dbi, sizeof(dbi));
    dbi.dbcc_size = sizeof(dbi);
    dbi.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
    dbi.dbcc_classguid = GUID_DEVINTERFACE_HID;

    _glfw.win32.deviceNotificationHandle =
        RegisterDeviceNotificationW(_glfw.win32.helperWindowHandle,
                                    (DEV_BROADCAST_HDR*)&dbi,
                                    DEVICE_NOTIFY_WINDOW_HANDLE);
  }

  while (PeekMessageW(&msg, _glfw.win32.helperWindowHandle, 0, 0, PM_REMOVE)) {
    TranslateMessage(&msg);
    DispatchMessageW(&msg);
  }

  return GLFW_TRUE;
}

//////////////////////////////////////////////////////////////////////////
//////                       GLFW internal API                      //////
//////////////////////////////////////////////////////////////////////////

// Returns a wide string version of the specified UTF-8 string
//
WCHAR* _glfwCreateWideStringFromUTF8Win32(const char* source) {
  WCHAR* target;
  int count;

  count = MultiByteToWideChar(CP_UTF8, 0, source, -1, NULL, 0);
  if (!count) {
    _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
                         "Win32: Failed to convert string from UTF-8");
    return NULL;
  }

  target = calloc(count, sizeof(WCHAR));

  if (!MultiByteToWideChar(CP_UTF8, 0, source, -1, target, count)) {
    _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
                         "Win32: Failed to convert string from UTF-8");
    free(target);
    return NULL;
  }

  return target;
}

// Returns a UTF-8 string version of the specified wide string
//
char* _glfwCreateUTF8FromWideStringWin32(const WCHAR* source) {
  char* target;
  int size;

  size = WideCharToMultiByte(CP_UTF8, 0, source, -1, NULL, 0, NULL, NULL);
  if (!size) {
    _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
                         "Win32: Failed to convert string to UTF-8");
    return NULL;
  }

  target = calloc(size, 1);

  if (!WideCharToMultiByte(CP_UTF8, 0, source, -1, target, size, NULL, NULL)) {
    _glfwInputErrorWin32(GLFW_PLATFORM_ERROR,
                         "Win32: Failed to convert string to UTF-8");
    free(target);
    return NULL;
  }

  return target;
}

// Reports the specified error, appending information about the last Win32 error
//
void _glfwInputErrorWin32(int error, const char* description) {
  WCHAR buffer[_GLFW_MESSAGE_SIZE] = L"";
  char message[_GLFW_MESSAGE_SIZE] = "";

  FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM |
                     FORMAT_MESSAGE_IGNORE_INSERTS |
                     FORMAT_MESSAGE_MAX_WIDTH_MASK,
                 NULL,
                 GetLastError() & 0xffff,
                 MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                 buffer,
                 sizeof(buffer) / sizeof(WCHAR),
                 NULL);
  WideCharToMultiByte(CP_UTF8, 0, buffer, -1, message, sizeof(message), NULL, NULL);

  _glfwInputError(error, "%s: %s", description, message);
}

// Updates key names according to the current keyboard layout
//
void _glfwUpdateKeyNamesWin32(void) {
  int key;
  BYTE state[256] = {0};

  memset(_glfw.win32.keynames, 0, sizeof(_glfw.win32.keynames));

  for (key = GLFW_KEY_SPACE; key <= GLFW_KEY_LAST; key++) {
    UINT vk;
    int scancode, length;
    WCHAR chars[16];

    scancode = _glfw.win32.scancodes[key];
    if (scancode == -1)
      continue;

    if (key >= GLFW_KEY_KP_0 && key <= GLFW_KEY_KP_ADD) {
      const UINT vks[] = {
          VK_NUMPAD0, VK_NUMPAD1, VK_NUMPAD2, VK_NUMPAD3, VK_NUMPAD4, VK_NUMPAD5, VK_NUMPAD6, VK_NUMPAD7, VK_NUMPAD8, VK_NUMPAD9, VK_DECIMAL, VK_DIVIDE, VK_MULTIPLY, VK_SUBTRACT, VK_ADD};

      vk = vks[key - GLFW_KEY_KP_0];
    } else
      vk = MapVirtualKey(scancode, MAPVK_VSC_TO_VK);

    length = ToUnicode(vk, scancode, state, chars, sizeof(chars) / sizeof(WCHAR), 0);

    if (length == -1) {
      length = ToUnicode(vk, scancode, state, chars, sizeof(chars) / sizeof(WCHAR), 0);
    }

    if (length < 1)
      continue;

    WideCharToMultiByte(CP_UTF8, 0, chars, 1, _glfw.win32.keynames[key], sizeof(_glfw.win32.keynames[key]), NULL, NULL);
  }
}

// Replacement for IsWindowsVersionOrGreater as MinGW lacks versionhelpers.h
//
BOOL _glfwIsWindowsVersionOrGreaterWin32(WORD major, WORD minor, WORD sp) {
  OSVERSIONINFOEXW osvi = {sizeof(osvi), major, minor, 0, 0, {0}, sp};
  DWORD mask = VER_MAJORVERSION | VER_MINORVERSION | VER_SERVICEPACKMAJOR;
  ULONGLONG cond = VerSetConditionMask(0, VER_MAJORVERSION, VER_GREATER_EQUAL);
  cond = VerSetConditionMask(cond, VER_MINORVERSION, VER_GREATER_EQUAL);
  cond = VerSetConditionMask(cond, VER_SERVICEPACKMAJOR, VER_GREATER_EQUAL);
  // HACK: Use RtlVerifyVersionInfo instead of VerifyVersionInfoW as the
  //       latter lies unless the user knew to embed a non-default manifest
  //       announcing support for Windows 10 via supportedOS GUID
  return RtlVerifyVersionInfo(&osvi, mask, cond) == 0;
}

// Checks whether we are on at least the specified build of Windows 10
//
BOOL _glfwIsWindows10BuildOrGreaterWin32(WORD build) {
  OSVERSIONINFOEXW osvi = {sizeof(osvi), 10, 0, build};
  DWORD mask = VER_MAJORVERSION | VER_MINORVERSION | VER_BUILDNUMBER;
  ULONGLONG cond = VerSetConditionMask(0, VER_MAJORVERSION, VER_GREATER_EQUAL);
  cond = VerSetConditionMask(cond, VER_MINORVERSION, VER_GREATER_EQUAL);
  cond = VerSetConditionMask(cond, VER_BUILDNUMBER, VER_GREATER_EQUAL);
  // HACK: Use RtlVerifyVersionInfo instead of VerifyVersionInfoW as the
  //       latter lies unless the user knew to embed a non-default manifest
  //       announcing support for Windows 10 via supportedOS GUID
  return RtlVerifyVersionInfo(&osvi, mask, cond) == 0;
}

//////////////////////////////////////////////////////////////////////////
//////                       GLFW platform API                      //////
//////////////////////////////////////////////////////////////////////////

int _glfwPlatformInit(void) {
  // To make SetForegroundWindow work as we want, we need to fiddle
  // with the FOREGROUNDLOCKTIMEOUT system setting (we do this as early
  // as possible in the hope of still being the foreground process)
  SystemParametersInfoW(SPI_GETFOREGROUNDLOCKTIMEOUT, 0, &_glfw.win32.foregroundLockTimeout, 0);
  SystemParametersInfoW(SPI_SETFOREGROUNDLOCKTIMEOUT, 0, UIntToPtr(0), SPIF_SENDCHANGE);

  if (!loadLibraries())
    return GLFW_FALSE;

  createKeyTables();
  _glfwUpdateKeyNamesWin32();

  if (_glfwIsWindows10CreatorsUpdateOrGreaterWin32())
    SetProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
  else if (IsWindows8Point1OrGreater())
    SetProcessDpiAwareness(PROCESS_PER_MONITOR_DPI_AWARE);
  else if (IsWindowsVistaOrGreater())
    SetProcessDPIAware();

  if (!_glfwRegisterWindowClassWin32())
    return GLFW_FALSE;

  if (!createHelperWindow())
    return GLFW_FALSE;

  _glfwInitTimerWin32();
  _glfwInitJoysticksWin32();

  _glfwPollMonitorsWin32();
  return GLFW_TRUE;
}

void _glfwPlatformTerminate(void) {
  if (_glfw.win32.deviceNotificationHandle)
    UnregisterDeviceNotification(_glfw.win32.deviceNotificationHandle);

  if (_glfw.win32.helperWindowHandle)
    DestroyWindow(_glfw.win32.helperWindowHandle);

  _glfwUnregisterWindowClassWin32();

  // Restore previous foreground lock timeout system setting
  SystemParametersInfoW(SPI_SETFOREGROUNDLOCKTIMEOUT, 0, UIntToPtr(_glfw.win32.foregroundLockTimeout), SPIF_SENDCHANGE);

  free(_glfw.win32.clipboardString);
  free(_glfw.win32.rawInput);

  _glfwTerminateWGL();
  _glfwTerminateEGL();

  _glfwTerminateJoysticksWin32();

  freeLibraries();
}

const char* _glfwPlatformGetVersionString(void) {
  return _GLFW_VERSION_NUMBER " Win32 WGL EGL OSMesa"
#if defined(__MINGW32__)
                              " MinGW"
#elif defined(_MSC_VER)
                              " VisualC"
#endif
#if defined(_GLFW_USE_HYBRID_HPG) || defined(_GLFW_USE_OPTIMUS_HPG)
                              " hybrid-GPU"
#endif
#if defined(_GLFW_BUILD_DLL)
                              " DLL"
#endif
      ;
}
